WO1998014815A1

WO1998014815A1 - Adjustable reflector

Info

Publication number: WO1998014815A1
Application number: PCT/EP1997/005122
Authority: WO
Inventors: Stephen C. O'hara-Smith
Original assignee: Hara Smith Stephen C O
Priority date: 1996-10-01
Filing date: 1997-09-18
Publication date: 1998-04-09
Also published as: PT929833E; DE59705702D1; EP0929833A1; DE29617111U1; EP0929833B1; AU4704197A; AU722115B2; IL129041A0; US6227673B1; ES2168612T3; IL129041A

Abstract

The invention concerns an adjustable reflector (1) which comprises a plurality of reflector elements (2) which each have a reflector surface (3) and are pivotably disposed. The reflector elements (2) can pivot in at least two directions and/or are mutually coupled and pivotable together. The reflector surface (3) can comprise a tensioned aluminium or silver foil. The reflector elements (2) can be at least partially transparent spheres. According to a further configuration, the reflector surface is disposed in an equatorial plane of the spheres. It can be produced in a particularly advantageous manner from the point of view of manufacturing techniques if the spheres are each assembled from two hemispheres, the reflector surface being formed on the flat surface of one of the two hemispheres. Preferably, in order to be parallel and jointly pivotable, the reflector elements can be coupled in a particularly structurally simple and elegant manner if, according to a further advantageous embodiment of the invention, the spherical reflector elements are clamped between two plane parallel plates of which at least one is made of a transparent material. If one of these two plates is displaceable relative to the other plate whilst the spacing therebetween is maintained, a corresponding displacement rotates the spherical reflector elements, clamped between the two plates, in the same direction, such that the surface normal of their reflector surface is adjusted or pivoted in the desired manner.

Description

Adjustable reflector

The invention relates to an adjustable reflector.

Reflectors are commonly used to redirect electromagnetic radiation, such as light. Reflectors are often used for advertising purposes, in connection with signaling devices or for the purpose of directing sunlight in a certain direction, for example onto a solar collector. To change the angle of reflection, for example to adapt to a changing position of the sun, the reflectors must be pivoted.

From a certain size of the reflector, this requires structurally very extensive, complex and expensive gimbal mountings, which have to be particularly stable and therefore take up space when the reflector is exposed to wind forces. In any case, a reflector, which should be pivotable by 90 ° or more, occupies a space whose base area is in both

Directions corresponds to the maximum length dimensions of the reflector. It is therefore difficult to make an array of many larger reflectors when space is limited. The swiveling of a large and thus heavy reflector can only take place very slowly, since a large mass has to be moved precisely.

Based on these inadequacies and disadvantages of the prior art, the invention has for its object to provide an adjustable reflector that is comparatively small, resistant, robust and inexpensive to manufacture and that with comparatively less expensive devices in short

Response times can be aligned, i.e. adjusted. This object is achieved in that the adjustable reflector has a plurality of reflector elements, each having a reflector surface, which are arranged pivotably.

In order to change the direction of the surface normal of the reflector surface and thus the direction of the reflected beam, it is no longer necessary with the reflector according to the invention to align the entire, often very voluminous reflector; Rather, it is sufficient to adjust the individual reflector elements which are pivotably arranged according to the invention in such a way that the surface normal of their respective reflector surface has a desired direction and thus a desired direction

Angle of reflection.

According to a particularly advantageous embodiment of the invention, the reflector elements can be pivoted in at least two directions, so that the surface normal of the reflector elements is in almost any direction in the region of one

Can sweep over the hemisphere.

It is particularly advantageous if the reflector elements are mutually coupled and pivotable together, preferably in parallel. An individual adjustment of the individual reflector elements is not necessary.

The reflector surface can, in particular if the reflector is to be used for visible light, consist of a stretched aluminum or silver foil.

According to a further advantageous embodiment of the invention as

Reflector elements used at least partially transparent balls. These can be made of glass or plastic. Glass is preferable because of its optical properties, while plastic balls are cheaper to manufacture.

According to a further embodiment, it is provided that the reflector surface is arranged in an equatorial plane of the balls. This can be realized particularly favorably from the point of view of production technology if the balls are each composed of two hemispheres, the reflector surface being formed on the flat surface of one of the two hemispheres. A coupling of the reflector elements for parallel joint pivoting of the same can be achieved in a structurally particularly simple and elegant manner if, according to a further advantageous embodiment of the invention, the spherical reflector elements are clamped between two plane-parallel plates, at least one of which consists of a transparent material.

If one of these two plates is displaceable relative to the other of the plates while maintaining their distance, the spherical reflector elements clamped between the two plates are rotated in the same direction by a corresponding displacement, as a result of which the surface normal of their reflector surfaces is adjusted or pivoted in the desired manner. A relative movement between the two plates in the order of magnitude of a circumference of the reflector balls allows the surface normals of the reflector surfaces to be pivoted through 180 °. This means that with a preferred ball diameter of, for example, 2.5 cm and a ball circumference of approximately 7.85 cm, the full adjustment range of 180 ° is covered when a plate is moved by 7.85 cm. In practice, however, much smaller adjustment ranges are sufficient. Because of the short adjustment paths, the adjustment can be carried out within a few seconds, while adjustment times of a few hours are not uncommon for reflectors according to the prior art. As a result of the short reaction times in the invention

This reflector can also be used in demand-controlled systems in which there is the problem of changing the performance of a solar collector with a short response time by adjusting or "misaligning" the reflector.

According to a further advantageous embodiment of the invention, a device for displacing at least one of the two plates relative to the other of the two plates in a first direction is provided. It is also advantageous if a further device is provided which enables one of the two plates to be displaced in a second direction perpendicular to the first direction. With two such devices, any desired direction of the surface normal of the reflection surfaces can be set in a solid angle of a hemisphere (2π).

The device or devices for displacing at least one of the two

Plates in mutually perpendicular directions can consist of simple, manually operated adjustment spindles. According to a particularly advantageous embodiment of the According to the invention, however, a motor is provided for this purpose, which enables a continuous adjustment of the displacement in the first and / or in the second direction of at least one of the two plates relative to the other of the two plates. It is preferably a linear or stepper motor with a gear. This embodiment of the invention enables convenient adjustment of the

Area normal and thus the angle of reflection, possibly also remotely controlled or - according to a further preferred embodiment - controlled by a computer-aided system. For example, with a computer-aided system, the angle of reflection when using the reflector in conjunction with a solar collector can track the changing position of the sun in such a way that the solar radiation is optimally directed onto the solar collector. The computing capacity of an ordinary personal computer (PC) has proven to be sufficient for such a control, even if a series of reflectors has to be controlled.

In order to ensure a uniform contact pressure of the reflector elements clamped between the two plates, at least one of the two plates is preferably provided with an elastic substance, which is preferably a foam.

According to a preferred embodiment, provision is further made to arrange the adjustable reflector according to the present invention in a housing frame.

The invention is explained in more detail below on the basis of exemplary embodiments shown schematically in FIGS. 1 to 4. It shows:

Figure 1 is a perspective view of an adjustable reflector according to a first embodiment;

Figure 2 is a perspective view of a reflector element composed of two hemispheres;

3 shows a section along the section line III-III of FIG. 1; and

Figure 4: a section corresponding to the section of Figure 3 in a modified embodiment.

The adjustable reflector 1 shown in FIG. 1 has a first transparent plane-parallel plate 4, which can be made of glass or plastic. At a distance from the first plate 4 there is a second plate 5 parallel to it. Spherical reflector elements 2 are clamped between the two plates 4 and 5. In the drawing, a total of 7 x 12 spherical reflector elements 2 are provided, although in practice a much larger number of reflector elements 2 can of course be provided depending on the overall size of the reflector. A typical size for a reflector 1 would be one square meter, for example. A typical size for the spherical reflector elements 2 would be, for example, 2.5 cm in diameter, the individual balls being arranged at a mutual distance of a few millimeters, so that approximately 35 balls and a total of approximately 1225 balls are contained in one reflector 1 in one direction.

The two plates 4 and 5 are connected to one another in an airtight manner by a bellows 12, so that no dirt can penetrate into the interior space enclosed by the two plates 4 and 5. Nevertheless, the two plates 4 and 5 are not rigidly connected to one another, but rather can be moved against one another within their plane within certain limits.

Figure 2 shows the structure of a reflector element 2. As can be seen from Figure 2, a reflector element 2 is composed of two transparent hemispheres 2a and 2b, which are preferably made of plastic. A reflector surface 3 in the form of a glued-on aluminum foil is attached to the cutting plane of the hemisphere 2b. The two hemispheres 2a and 2b shown separately in FIG. 2 for illustration purposes are glued to one another by means of an adhesive.

The reflector elements 2 constructed in this way are held in the adjustable reflector 1 shown in FIG. 1 between the two plates 4 and 5 by static friction. This is assisted by an elastic foam layer attached to the plate 5 lying at the rear in FIG. 1, which ensures that all reflector elements 2 are subject to the same contact pressure within wide limits, which is sufficient to frictionally engage them without slipping between the two plates 4 and 5 respectively. The two plates 4 and 5 are movably mounted in a rectangular frame 11. The frame consists of two vertical branches 11 a and two horizontal branches 11 b. With the chosen type of storage, a displacement of the plate 4 in the vertical direction (vertical with respect to the illustration in FIG. 1) and a displacement of the plate 5 in the horizontal direction (horizontal with respect to the illustration in FIG. 1) are possible.

For this purpose, the plate 4 is provided with a total of four sliding feet 13, each of which engages in corresponding guide grooves 14 provided on the vertical branches 11 a of the frame 11.

By means of a threaded spindle 6 which is in a threaded bore of a horizontal branch

11 b of the frame 11 is guided and the tip of which is connected to the plate 4, the plate 4 can be precisely displaced in parallel in the vertical direction, the movement taking place exactly in the plane of the plate 4. In the same way, the plate 5 lying at the rear in the illustration in FIG. 1 is provided with sliding feet 15 which in the guide grooves (not recognizable in the illustration in FIG. 1) in the FIGS

Engage horizontal branches 1 1 b of the frame 11 and thus allow a horizontal displacement of the plate 5. By means of a further threaded spindle 7, which is guided in a threaded bore of a vertical branch 11 a of the frame 11, the rear plate 5 can be positioned precisely in the horizontal direction. By guiding the two plates 4 and 5 it is ensured that they always remain parallel and their mutual distance remains constant, so that the spherical reflector elements 2 clamped between the plates 4 and 5 are always pressed with constant force.

By actuating the threaded spindle 6 and an associated vertical

Displacement of the plate 4 (vertically with respect to the illustration in FIG. 1), the alignment of the reflector surfaces 3 in the vertical direction can be achieved. A displacement of the plate 4 by only a few centimeters is sufficient to set practically any desired angle in the vertical direction. Elaborate and space-consuming pivoting devices of the reflector are not required.

In the same way, by horizontally shifting the rear plate 5 (horizontally with respect to the illustration in FIG. 1), the surface normals of the reflector surfaces 3 can be adjusted at any desired angle by just shifting a few centimeters. In the sectional view of FIG. 3 it can be seen particularly well how the spherical reflector elements 2 are clamped between the plates 4 and 5 sealed by the bellows 12. In Figure 3, in particular the sliding feet 13 arranged on the plate 4 can be seen, which slide in the guide groove 14 in order to enable a vertical displacement of the plate 4 (vertical with respect to the illustration in Figure 3), for which purpose the adjusting spindle 6 is actuated .

Furthermore, the sliding feet 15 can be seen in FIG. 3, which are guided in the horizontal branches 11b of the frame 11 in order to ensure that the plate 5 is guided horizontally.

FIG. 4 shows a representation of a modified exemplary embodiment corresponding to the sectional representation of FIG. 3. In this embodiment, in which again the reflector elements 2 are clamped between two plates 4 and 5, one of the two plates, namely the transparent plate 4, is firmly connected to a frame (not shown). Only the plate 5 is movably supported, a motor 10 with gear and a drive wheel 16 frictionally connected to the plate 5 being used to move the same. By means of this drive device 8 consisting of the motor 10 with gear and the drive wheel 16, the plate 5 can be moved perpendicular to the plane of the drawing, ie in the horizontal direction. A corresponding device 9 for moving the plate 5 in the vertical direction is constructed accordingly, but is pivoted through an angle of 90 °. Details of the fastening of the drive devices 8 and 9 have been omitted for reasons of clarity.

Claims

Expectations

1 . Adjustable reflector (1), characterized in that it has a plurality of reflector elements (2) each having a reflector surface (3) which are arranged pivotably.

2. Reflector according to claim 1, characterized in that the reflector elements

(2) are pivotable in at least two directions.

3. Reflector according to claim 1 or 2, characterized in that the reflector elements (2) are mutually coupled and jointly pivotable.

4. Reflector according to at least one of claims 1 to 3, characterized in that the reflector surface (3) has a stretched aluminum or silver foil.

5. A reflector according to at least one of claims 1 to 4, characterized in that the reflector elements (2) are at least partially transparent balls.

6. Reflector according to claim 5, characterized in that the reflector surface

(3) is arranged in an equatorial plane of the balls.

7. A reflector according to claim 5 or 6, characterized in that the balls each consist of two hemispheres (2a, 2b).

8. Reflector according to claim 7, characterized in that at least one of the two hemispheres (2a, 2b) consists of a transparent material.

9. Reflector according to at least one of claims 5 to 8, characterized in that the balls are clamped between two plane-parallel plates (4, 5), of which at least one plate (4) consists of a transparent material.

1 0. Reflector according to claim 9, characterized in that at least one of the two plates (4, 5) relative to the other of the two plates (5, 4) is displaceable while maintaining its distance from the other plate.

1 1. Reflector according to claim 10, characterized in that a device (6;

9) for displacing at least one of the two plates (4, 5) relative to the other of the two plates (5, 4) in a first direction.

1 2. Reflector according to claim 1 1, characterized in that a device (7; 8) for displacing at least one of the two plates (4, 5) relative to the other of the two plates (5, 4) in a second, to the first direction vertical direction is provided.

1 3. A reflector according to claim 1 1 or 12, characterized in that the devices (8, 9) for displacement have a motor (10), the continuous adjustment of the displacement in the first and / or in the second direction at least one of the provides two plates (4, 5) relative to the other of the two plates (5, 4).

1 4. Reflector according to claim 13, characterized in that it is in the

Motor (10) is a linear or stepper motor with gear.

1 5. reflector according to at least one of claims 1 1 to 14, characterized in that the device (8, 9) for displacement in the first and / or in the second direction is controlled by a computer-aided system.

1 6. Reflector according to at least one of claims 9 to 15, characterized in that at least one of the two plates (4, 5) on the side facing the reflector elements (2) with an elastic substance for uniform distribution of the pressure on the reflector elements (2 ) coated is.

7. A reflector according to claim 16, characterized in that the substance is foam.

8. A reflector according to at least one of claims 1 to 17, characterized in that it is arranged in a housing frame (11).